CVE-2026-8247 WatchGuard Firebox admd Out of Bounds Write Vulnerability

What is CVE-2026-8247?

CVE-2026-8247 is a high-severity memory corruption vulnerability in Watchguard Fireware, published on 2 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

An Out-of-bounds Write vulnerability in WatchGuard Fireware OS may allow an unauthenticated attacker on the same local network segment to execute arbitrary code.

This vulnerability affects Fireware OS 11.0 up to and including 11.12.4_Update1, 12.0 up to and including 12.12 and 2025.1 up to and including 2026.2.

Weakness: CWE-787, CWE-120

Which versions are affected by CVE-2026-8247?

It affects 1 product.

Products include Watchguard Fireware.

How do I fix CVE-2026-8247?

No fix has been published for CVE-2026-8247 yet. Limit exposure of the affected software until one is available.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2026-8247 being exploited?

There is no known exploitation of CVE-2026-8247 in the wild and no public exploit code.

Other vulnerabilities in Watchguard Fireware

• CVE-2022-26318 WatchGuard Firebox and XTM Appliances Arbitrary Code Execution Exploited Critical 9.8
• CVE-2025-14733 WatchGuard Firebox Out of Bounds Write Exploited Critical 9.3
• CVE-2025-9242 WatchGuard Firebox Out-of-Bounds Write Exploited Critical 9.3
• CVE-2022-23176 WatchGuard Firebox and XTM Privilege Escalation Exploited High 8.8
• CVE-2022-31789 Integer overflow in n/a Critical 9.8

All Watchguard Fireware vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-h2w9-p676-66ch.